Answer:
Option c: Possible electron energy states are quantized within an atom.
Explanation:
The Bohr's Model of the hydrogen atom consisted of the movements of the electrons around the positively-charged nucleus in circular orbits that have a certain energy state. The energy of that orbit is given by:

<em>Where:</em>
E(n): is the energy of an electron in a particular orbit
R: is the Rydberg constant
h: is the Plank constant
c: is the speed of light
n: is a positive integer which corresponds to the number of the orbit
The ground state energy of a electron in the hydrogen atom is equal to -13,6 eV.
Bohr's Model aims to propose that the electron is restrictedly to occupy a certain region in the atom.
Therefore, the conclusion of Bohr after observing emission spectrum lines is that "possible electron energy states are quantized within an atom", so the correct option is c.
I hope it helps you!
Answer:
a. Volatile.
b. Air foil.
c. Sash.
d. Work surface.
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are;
I. Solid.
II. Liquid.
III. Gas.
Matching the terms with their respective definition, we have;
a. Volatile: A characteristic that describes substances that evaporate readily, producing large amounts of vapors.
b. Air foil: the front vent of a fume hood, which helps maintain proper air circulation.
c. Sash: the glass panel in front of the fume hood that shields the user from fumes and other hazards.
d. Work surface: the horizontal, flat area of a fume hood upon which experiments are carried out.
Two non metal combined together and form the bond is called covalent bond
Note - yellow color molecules in pictures are non metal elements
example - co2 , so2,
Planets, black wholes gravity